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Main Boards => The Bowyer's Bench => Topic started by: USAFdad on October 24, 2012, 11:41:00 AM

Title: crack in limb glass
Post by: USAFdad on October 24, 2012, 11:41:00 AM
Building a couple TD bows for my boys for Christmas and the riser for one had a critical failure. There is a fracture in the glass of this limb now when it smacked the edge of the bench.
Question is can I save this, would it be fine with tha tip overlays glued over the top?
I already have a new limb kit ready to glue up but hate to waste these if I don't have to.
Thanks for your thoughts on the matter.
Title: Re: crack in limb glass
Post by: USAFdad on October 24, 2012, 11:44:00 AM
Sorry not good at the picture thing. Trying again                                           [IMG]http://i967.photobucket.com/albums/ae156/hualapai09/2012-10-24063330.jpg[/IMG
Title: Re: crack in limb glass
Post by: USAFdad on October 24, 2012, 11:50:00 AM
(http://i967.photobucket.com/albums/ae156/hualapai09/2012-10-24063330.jpg)
Hopefully third times a charm.
Title: Re: crack in limb glass
Post by: GREG IN MALAD on October 24, 2012, 01:24:00 PM
I would drill a .050 hole at the end of the crack so it doesn't grow, then fill the crack with thin superglue. With a tip overlay it should be fine. I have repaired similiar cracks this way with good results.
Title: Re: crack in limb glass
Post by: Swissbow on October 24, 2012, 02:25:00 PM
I would use a syringe to inject epoxy under the glass. With a hot air gun you can heat up the epoxy and make it very liquid. Due to the capillarity the epoxy fills out even the smallest crack almost by itself, just make sure to inject enough of it. It works perfect and after the epoxy has cured and everything is cleaned up you barely won't be able to see the repair job.

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Andy
Title: Re: crack in limb glass
Post by: LittleBen on October 24, 2012, 03:43:00 PM
Both those plans sound solid. I'd probably drill the .050 hole at the tip of the crack as suggested by Greg and then use the epoxy injection as suggested by Andy. Then definately tip overlay. Maybe use some phenolic for the overlay then a bit of hardwood.
Title: Re: crack in limb glass
Post by: USAFdad on October 24, 2012, 04:11:00 PM
Thanks for the great advise so far. You've just made my day guys. I was hoping that there was a possibility this limb could be saved.

So where does one aquire a suitable syringe for the task?  Do I just use any clear epoxy or are we talking smooth-on?

I had planned on phenolic and hardwood tip overlay and I think it's called kwik-it glue, a super glue type of glue I got from a friend.
Title: Re: crack in limb glass
Post by: wood carver 2 on October 24, 2012, 06:21:00 PM
I got an unused but expired syringe from a doctor when I explained that I needed one for injecting glue into cracks to repair furniture.
Once I'm done, I just wash it out so it can be used again. It might have helped that I had just built a nice blanket chest for her.  :knothead:  
Dave.
Title: Re: crack in limb glass
Post by: rmorris on October 24, 2012, 11:39:00 PM
Here is a crazy trick for you... Once you follow all of the other advices on stoping and filling the crack  and if you dont want to do an overlay, take a brown sharpie and draw over the crack very lightly . This will nearly make any blimish in the glass go away and you can then put a normal finish over the sharpie. Also if you don't like it , take some alchoal and remove the sharpie.
Title: Re: crack in limb glass
Post by: USAFdad on October 25, 2012, 11:22:00 AM
Thanks again for all the advise.
rmorris, you reminded me of something. I saw the people at Lazy Boy furniture do the brown marker thing on an end table once. They had a whole kit full of different shades. It did work well.